How can I tell if we ruined the cruciate repair surgery because of a post-surgery jump?

My Yorkie had surgery to repair a torn cruciate ligament (left extracapsular repair) yesterday. He has been on strict cage rest since then. Just now, when we took him out of the cage, he jumped down before anyone could react. We aren't sure if he landed on his leg or not. The vet is closed for the night, and when we phoned the emergency vet she said it is unlikely he landed on his leg so soon after surgery. It's difficult to tell if he has torn it unless you are the surgeon, but are there any external signs to look for? We are so worried, and the leg is already swollen from surgery.